Line2 - Line2 adds a second phone number or complete cloud business phone system to smartphones & computers that's robust yet affordable. Buy online or get a custom quote.
Google Voice - Google Voice gives you one number for all your phones, voicemail organized in an email format, free...
Phone.com - VOIP Business Phone Service + Virtual PBX
TextMe - TextMe is a free calls and messaging application at both local and international levels.
RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
Talkatone - Android App on. Google Play. Stop paying for cell minutes, texts & landlines; Turn your iPad or iPod touch into a phone; Call/Text even in areas with bad cell coverage; Call/Text when travelling without paying for expensive international minutes.